The fleet admiral insignia for the system used after TNG Season 1 would be five pips enclosed in a rectangular border. At this point, this insignia has not been identified in any onscreen source, but is derived from the Star Trek Encyclopedia. The rank has been canonically mentioned in that era, however, but the officers in question wore the insignia of lower ranked admirals, a possible costume mistake, or simply a confusion in nomenclature (they were admirals in command of fleets, but perhaps not fleet admirals). Possibly this rank is only differentiated by this insignia under special circumstances, such as wartime.

Immediately superior to a captain, and just before rear admiral. At some point in Starfleet history, this rank became known as "rear admiral lower half."

This practice mirrors a change made in the modern-day US Navy eliminating the commodore grade. In TOS, many fleet commanders and other senior personnel were commodores, but by TNG, an officer (Admiral Gregory Quinn) with an equivalent insignia to a commodore was referred to as an admiral, indicating Starfleet made a similar change.

Fleet Captain is a title bestowed on highly distinguished Starfleet captains. It is an extremely rare distinction, held by senior or particularly distinguished captains. It was held by former Enterprise captain Christopher Pike in the year 2266. It was also held in the 2260s, by Captain Garth, one of Starfleet's most decorated captains and hero of the Battle of Axanar.

Although not officially used after TOS, the rank of Fleet Captain was assigned an official rank pin in the movie-era set of ranks established for Star Trek II through Star Trek VI. The pin was the same as the captain's rank pin, but with two additional "flags" attached to the long edges of the pin. In addition, some fan publications do carry the Fleet Captain rank into the TNG era, using five solid pips to designate the rank.

The most senior regular line rank in Starfleet. It is most often applied to starship and starbase commanders, and the adjutants and executives serving beneath admirals. This rank is usually considered a big transition, because it is often the first rank in which officers run a base of operation (i.e. a starship) more or less by themselves. The equivalent military rank to Starfleet captain is colonel.

In the modern US Navy, captain is a four-stripe officer rank. This insignia style was used in ENT and all TNG era productions. During TOS and the movies, it had differing insignia. The TOS captains wore one full braid, a broken braid and another full braid. However, in the pilot "The Cage", Captain Pike wore only a single rank strip, so it was not clear how other officers were differentiated from captains. By "Where No Man Has Gone Before", Kirk was the only officer with two stripes, but that system didn't differentiate any other officer grades below captain except for no-stripe ensigns.

The Starfleet line rank immediately inferior to Captain. Officers at this rank typically hold positions such as space station commander (e.g. Sisko prior to 2372) or first officer of important starships (e.g. Riker, on the Enterprise-D from 2364 – 2379). Line officers reaching this rank typically have between 10 and 15 years of experience in Starfleet.

The Starfleet line rank immediately inferior to Commander. Officers with this rank typically hold positions as starship department heads (e.g., Montgomery Scott, Geordi La Forge), or, in some cases, as commanding officer (e.g., Piersall aboard the Prometheus) or first officer of a starship (e.g., Benjamin Sisko aboard the Saratoga, Christopher Hobson aboard the Sutherland, or Cavit aboard Voyager prior to his death when Voyager was thrown deep into the Delta Quadrant).

The Starfleet line rank immediately inferior to Lieutenant Commander. Officers at this rank typically have some command experience, and are occasionally appointed department heads on starships. Typically they are shift commanders in a department under a Lieutenant Commander, i.e. a Lt. Commander will be chief of engineering and will also be commander of A shift, and there will be a B and C shift, each under a Lieutenant.

The Starfleet line rank immediately inferior to Lieutenant. Officers at this rank typically hold support positions on starships and starbases. At this rank, they have begun to prove their ability to perform acceptably in Starfleet, and typically begin to take on more senior roles in command situations. On rare occasions, Starfleet Cadets who post highly distinguished records at Starfleet Academy are granted the rank of Lieutenant Junior Grade upon graduation, bypassing the traditional junior rank of Ensign. Dr. Julian Bashir is an example of one such officer. Other officers to whom this has been conjectured to happen include Lieutenant Saavik of Vulcan.

In the modern US armed forces, service members may begin their career as an officer at the rank of lieutenant or lieutenant commander if, due to the nature of their occupation, they were required to continue their education beyond the level of a Bachelors degree prior to receiving their initial commission. This is normally for members serving in non-line officer roles, such as Judge Advocate General Corps (JAG), Medical Service Corps and scientific researchers. Starfleet may utilize a similar policy for commissioning officers.

Typical posts at this rank are conn officer, communications officer or second officer of a shift (see lieutenant).

The most junior Starfleet Line rank. It is the rank bestowed on newly commissioned officers when they graduate from Starfleet Academy. Ensigns typically begin their careers as the most junior officers in the department of their chosen specialty. Ensigns who have strongly distinguished themselves in their academy class or on duty may sometimes be given posts as main-shift bridge officers (e.g. Ensign Harry Kim). A typical officer spends approximately three years at the rank of Ensign. (TNG: "Datalore")

↑The rank of commodore was mostly phased out in the 2350s in favor of the rank of rear admiral lower half.

↑ 5.05.1In the early 2250s, all officers, regardless of rank, wore one stripe. However, the rank scheme was later changed in the late 2250s and Captains wore two stripes, while all other officers still wore one.